LibDem Voice Co-Editor and ConservativeHome columnist Stephen Tall has set out the rationale for Nick Clegg’s challenge to Nigel Farage. He explains why Clegg has “little to lose, much to gain”, and how his gambit has thrown Farage on the defensive. None the less, there is a potential downside for the LibDem leader. Stephen writes of Farage: “If he agrees to Nick’s challenge, will it weaken his case for appearing in 2015′s televised leaders’ debates?” But what’s good for the UKIP goose is also good for the LibDem gander. Were Farage to agree to a scrap with Clegg, it would weaken the latter’s case for appearing in those debates, too – if they happen.

Furthermore, now that Clegg is pressing for a joust on the EU it follows that he could scarcely run away from one. This is why William Hague should promptly issue a challenge – and see just how much Clegg really wants that debate. The idea makes sense. The two men are of roughly the same seniority: one is Deputy Prime Minister, the other the deputy leader of his party (in effect). As Foreign Secretary, Hague is the right Conservative politician to discuss the Party’s EU policy, since he is responsible for it. And he is a skilled debater. So he would surely relish the prospect of taking on Clegg.

There is a further reason why such a scrap would be a good thing. Clegg could explain why the Liberal Democrats promised an In-Out referendum in 2010, and then promptly reneged on their election pledge. And Hague could reveal the Conservative approach to renegotiation and reform, which is rather under-revealed at the moment – perilously so.